Technical Field
The present invention relates to a gas sensor element detecting the concentration of a specific gas component in a measuring gas.
Background Art
Gas sensor elements detecting the concentration of a specific gas component are typically disposed in a site where an exhaust gas is emitted, such as in an exhaust pipe of an engine, to detect the concentration of nitrogen oxide (NOx), hydrocarbon (HC) or the like contained in the exhaust gas as a measuring gas.
For example, in the gas sensor element of PTL 1, a pair of electrodes are provided to a solid electrolyte body to form an oxygen pump cell, an oxygen monitor cell and a sensor cell. The gas sensor element detects the concentration of a specific gas component in a measuring gas introduced into the inner space thereof. The gas sensor element of PTL 1 aims to detect the concentration of a specific gas component without being affected by the oxygen concentration in the inner space. To this end, the ends of an electrode of the oxygen monitor cell and an electrode of the sensor cell, the ends being located upstream of a gas stream, are ensured to be equally distanced from a gas inlet through which a measuring gas is introduced into the inner space.